Android Question GPS start parameters

The 0 is the speed to aquire a fix, 0 means as quick as possible. The 100 means don't update the position if it is within 100 meters of the last position.

Hope I got that right.

First parameter is minimum time in milliseconds, second is minum distance in meters.
GPS1.Start(1000,100)
take lat/long each 1000ms or each 100 meters
if you are within 100 meters of the last position, you'll have a lat/long each 1000ms
if you move 100 meters before 1000ms the you also will have a lat/long.

GPS1.Start(0,100)
If you don't move you will not get lat/long.

To start test GPS i think is better begin with something like GPS1.Start(100,5)
Once your code works you can test other parameters to save battery.

If you don't have battery problems, best is GPS1.Start(0,0)

Thank you, but my case is:
I have a ServiceStartAt because the service must to start every 1 minute.
I have need not take lat/lon if I not move.
However in this case I take lat/long always (every 1 minues).
So in GPS_LocationChanged sub I was forced to test first 8 char of every lat/lon that takes.
How can I do better?

This parameter is not relevant for your program as you are only listening to the first event.

Also note that it is only a hint to the system. You cannot rely on it if the distance is important for you. Instead use the Geodesic class to calculate the distance.

Note that there is a bug in your code. You should not call GPS.Start multiple times without stopping the GPS (as will happen if it takes longer than one minute to get a fix).

Thanks Erel, but how do I know if I do not have GPS signal?
There isn't any event that tell me so.
If Locationchanged not run, how can I do?

Not sure that I understand the question. You will not be able to retrieve the location from the GPS until there is a fix.

Yes, I understand, then the question is:
if I haven't location GPS don't stop, then how do I stop the gps?
You said before "Start multiple times without stopping"

You can always call GPS.Stop. However a better solution is to avoid calling GPS.Start if it is already running. You can use a process global variable to track the state.